Well, I don't know you aussiegirl or what you know about pearls, but freshwater pearls are big in India. On my last tour through there, practically all I saw was vastly overpriced freshwater pearls, weakly pretending to be saltwater. Indian certifications are worth nothing when they just say, "hyderabad pearls"or "Basra" pearls. Those black pearls are dyed and that alone tells you they aren't worth much. They are freshwater pearls and everyone on this thread is correct- except you.
In India they never tell you if pearls are Tahitian, for instance, but the only naturally "black" pearls of any quality are from Tahiti and other such islands-from the black lipped, or margaritifera oyste,r and they usually have overtones other than black or silver, or they aren't worth much. Since this thread was stated back in July, we have had other pearls from India that deliberately obscure their origins by calling them "hyderabad pearls" and "basra" pearls and the sellers just get angry if you ask what kind of oyster they grew in. Unless I saw a good photo of your 20k necklace, I wouldn't believe it was Tahitian or Polynesian at all.
I would never buy pearls from India. They do not use the standard pearl ID practices and do not tell people what kind of pearls they are. If I didn't know freshwaters and what their prices in China were, I would have been fooled many times. ALL the pearls are called "Basra" pearls in their so-called "certifications" more and more are selling freshwaters for ridiculous prices based on their "reputation" from before the freshwater explosion since the 1980's or so. If that is what Swati calls "black pearls", then I would say the company is doing just that- riding on their pre-freshwater reputation and jacking up the price of freshwaters to near saltwater prices.
For 20k, I would invest in a GIA certification, because you can get the most magnificent Tahitian strands for far less than that. $20,000 would buy you a necklace with huge 14-15mm colorful pearls with very few pock marks, if any at all. And you can get a really marvelous Tahitian for less than 5k. Hyderabad has inflated pearl prices far beyond what the equivalent necklace will get anywhere else in the world.
For natural pearls in that part of the world, I would go to Bahrain, where pearls are exactly what the lab says they are and you will never find a cultured pearl until they change the very strict laws- which they have no intention of doing. That is where the genuine "Basra pearls" come from, not Hyderabad. India has a huge internal demand for pearls and they collected many before cultured pearls came into being. They tend to eschew the beaded pearls and like freshwaters because they are 100% nacre, like natural pearls, but try to sell them at vastly inflated prices. I never saw one honest price for freshwater pearls in India and I doubt it has changed, because freshwater pearls are even better than they were when I last went.
